I bought into the steel pin method. There are some advantages and disadvantages to this method. I use STP as a sizing lube. After sizing, I just toss the cases into the tumbler and add more Dawn to remove the oil. As previously stated, the cases come out clean inside and out.
On the negative side, the pins do have to be separated, and the cases dried. Most of the pins are separated when the cases are rinsed. After rinsing, I put the cases in a T-shirt that has the sleeves and neck sewn shut. A little tossing dries the cases somewhat, and removes most of the pins that are inside the cases. The cases are then dumped onto another T-shirt that is laid out on a table. I then use the magnetic end of an electic toothbrush to collect the pins from both T-shirts, the sink, and the floors. The "maid" gets real ****y when she finds them all over the house. lol
The most negative aspect of using the pins, is that they ding up the case mouth. This nessitates champfering the cases. I'm still experimenting in reducing the cleaning time to lessen the damage, and yet have clean cases.